KDM: to answer this in detail you need to crack open a book. Pick either Stephen Halbrook's "That Every Man Be Armed" (1984) or Akhil Reed Amar's "The Bill Of Rights" (1998).
Halbrook is a professor of law at George Mason and known for doing cases for the NRA - in other words, "one of us". Amar is a wildly Liberal Yale law professor.
Both books cover exactly the same material. Amar independently rediscovered (to his horror) what Halbrook had reported with glee earlier regarding the 14th Amendment, "selective versus full incorporation" and the privileges and immunities clause...and comments regarding same by John Bingham.
Trust me: all of this goes to the core of your question. Right now you don't know enough to ask the right questions...either book is a start and you only need one...they're damn near the same thing, same material, most of the same source material and quotes.
